================================================ Amazon SQS Transport - ``kombu.transport.SQS`` ================================================ .. currentmodule:: kombu.transport.SQS .. automodule:: kombu.transport.SQS .. contents:: :local: Transport --------- .. autoclass:: Transport :members: :undoc-members: Channel ------- .. autoclass:: Channel :members: :undoc-members: Back-off policy ------------------------ Back-off policy is using SQS visibility timeout mechanism altering the time difference between task retries. The mechanism changes message specific ``visibility timeout`` from queue ``Default visibility timeout`` to policy configured timeout. The number of retries is managed by SQS (specifically by the ``ApproximateReceiveCount`` message attribute) and no further action is required by the user. Configuring the queues and backoff policy:: broker_transport_options = { 'predefined_queues': { 'my-q': { 'url': 'https://ap-southeast-2.queue.amazonaws.com/123456/my-q', 'access_key_id': 'xxx', 'secret_access_key': 'xxx', 'backoff_policy': {1: 10, 2: 20, 3: 40, 4: 80, 5: 320, 6: 640}, 'backoff_tasks': ['svc.tasks.tasks.task1'] } } } ``backoff_policy`` dictionary where key is number of retries, and value is delay seconds between retries (i.e SQS visibility timeout) ``backoff_tasks`` list of task names to apply the above policy The above policy: +-----------------------------------------+--------------------------------------------+ | **Attempt** | **Delay** | +-----------------------------------------+--------------------------------------------+ | ``2nd attempt`` | 20 seconds | +-----------------------------------------+--------------------------------------------+ | ``3rd attempt`` | 40 seconds | +-----------------------------------------+--------------------------------------------+ | ``4th attempt`` | 80 seconds | +-----------------------------------------+--------------------------------------------+ | ``5th attempt`` | 320 seconds | +-----------------------------------------+--------------------------------------------+ | ``6th attempt`` | 640 seconds | +-----------------------------------------+--------------------------------------------+